The invention relates to an extra sheet feeder for a copying machine. In general, record sheets having a variety of sizes are provided, and are selectively used to suit a particular use. However, the usual copying machine is provided with a single paper feeder, and hence when it becomes necessary to use a record sheet of a different kind from the kind of record sheets which are already loaded into the copying machine, the loaded sheets must be removed from the machine and a desired record sheet must be loaded anew.
It is pointed out that there is a very strong desire or need to enable a copy to be obtained instantly on a record sheet of a different size from that of record sheets currently loaded in a machine or to obtain dual copies from copying machines which do not have the facility of providing such dual copies.
To accommodate for the need to provide a reduced number of copies of different size or dual copies, a record sheet or sheets are manually loaded into the paper feeder inlet of the machine as an extra sheet or sheets.
There are two types of extra sheet feeding means, one utilizing a devoted feeder which is associated with a separate feeder inlet for receiving an extra sheet or sheets only, and the other receiving the extra sheet into the usual inlet to be fed by the normal feed mechanism.
With feeding means of the former type, a separate feeder inlet must be provided for the extra sheet, which then must be fed by a manual operation, thus unavoidably resulting in a complicated control mechanism of the machine. By contrast, with the latter type, both the construction and the control can be simplified since the existing arrangement can be directly used. As examples of the latter type, U.S. Pat. No. 4,017,181 discloses a copying machine which utilizes a stack of record sheets received in a cassette, but in which when a copying on an extra sheet is desired, the cassette is removed out of the machine with a leading edge of the extra sheet inserted below a separator claw or claws which are provided on the cassette, which is then re-loaded into the machine. On the other hand, British Pat. No. 1,457,117 and U.S. Pat. No. 4,087,178 disclose an arrangement in which the top surface of a cassette which is externally visible when the cassette is loaded is provided with a plurality of indication marks representing a variety of sheet sizes and in which the leading edge of the extra sheet can be aligned with a feed position by aligning the trailing edge of the sheet with one of the indication marks.
In the arrangement of the initially cited U.S. Patent, the cassette must be withdrawn each time an extra sheet is to be loaded, requiring a troublesome operation and preventing an immediate operation. The other or latter PG,4 arrangement suffers from a problem that it cannot be assured that an extra sheet be loaded in place since the alignment with a selected indication mark cannot be achieved unless sheets of standardized sizes are used or a user may not be aware of the size of an extra sheet being used.
Some copying machines of the prior art are provided with a chamber in which a stack of record sheets of a given size is disposed, instead of using a cassette. When a copy on an extra sheet or a dual copy is desired, again the record sheets in the chamber must be removed, or an extra sheet must be engaged with a separator claw or claws which are provided on the chamber, thus resulting in the difficulty of use.